1. Field of the Invention
The present invention generally relates to an analog-to-digital converters and it particularly relates to an analog-to-digital converter of a pipeline type and that of a cyclic type in which analog signals are converted to digital signals in such a manner that an analog signal is circulated cyclically or a plurality of times in the same function block.
2. Description of the Related Art
In recent years, the mobile devices such as mobile phones are provided with an increasing variety of added functions including image shooting function, image playback function, moving image shooing function and moving image playback. Along with this trend, there is a growing demand for miniaturization, high accuracy, high speed and power saving of an analog-to-digital converter (hereinafter, referred to as an AD converter). One mode of AD converter that addresses this demand is known as a cyclic AD converter which cycles through stages (see, for example, Reference (1) in the following Related Art List).